A study of free-living nematode, Panagrolaimus (Nematoda: Rhabditida) using 18S rDNA from South Africa

Abstract

Bacterivorous nematodes are the main nematodes that live in the soil. Freeliving bacterivores are essential for the soil food web, biological control, and ecological study. Panagrolaimus belong to free-living bacterivorous nematode whichfeed on pathogenic bacteria, therefore, they can play an important role in the plant-pathogenic bacteria transmission. Besides, Panagrolaimus play a role in the nitrification of the minerals in the soil. Therefore, this molecular study was conducted in 2018 at the North West University to identify the bacterivorous nematodes from South Africa’ssoils using 18S rDNA marker. The recovered nematode was extracted using the tray method, and then its DNA was extractedusing the chelex method. The nematode was identified as Panagrolaimus. Afterward, 18S rDNA was amplified using specific primers to identify the nematode. The Nblast analysis based on the small subunit ribosomal DNA showed South African Panagrolaimus has 95% similarity (MK301117) with the Netherland population. Phylogenetic analysis using maximum likelihood placed this species with those molecularly identified as Panagrolaimus in the same clade with highly supported (100) bootstrap values. In conclusion, this species is identified using 18S rDNA properly. However, using other DNA markers for a betterunderstanding of Panagrolaimus phylogeny is recommended.